…because I just spent two weeks, R250 replacing, rewiring and testing a motor on my RepRap which didn’t appear to be working. I almost managed to blow the rest of the electronics fiddling and getting frustrated with it.
Turns out there was nothing wrong with the motor at all. The plastic cog attached to it had worn out just enough that it wasn’t turning with the spindle. A 10 minute, virtually cost free job to fix.